Corrosion-preventive hydrocarbon oil



2,344,016 CORROSION-PREVENTIVE HYDROCARBON OIL Alvin P. Anderson,Berkeley,

Qompany,

Shell Development Calm, assignor to San Francisco,

Calif., a corporation of Delaware No Drawing. Application March 25,1942, Serial No. 436,155

Claims.

ting power of the oil for the metal at these temperatures may. be highlyimportant. Tests have been developed for measuring the critical adhesiontemperatures of oils for metals, which tests show that a wide varietyexists between the critical adhesion temperatures of different types ofoils.

It is a purpose of this invention to produce a lubricating oil which hasa high critical adhesion temperature. It is another purpose to producean oil which not only does not withdraw from metals at hightemperatures, but on the contrary, tends to spread over them in spite ofthe high temperature. Another purpose is to produce ,oils which havepowerful anti-corrosive properties and which can be used for coatingfreshly machined metal parts to prevent their being attacked bymoisture.

I have discovered that the addition of a substance which I call waxamine and which will be described hereinafter in more detail, has thepeculiar property of greatly increasing the wetting power of minerallubricating oils or other refined liquid or solid hydrocarbons to whichit is added. This wetting power is greatly enhanced by the furtheraddition of a carboxylic acid having at least 12 carbon atoms.Hydrocarbon oils to which the invention is particularly applicablecomprise oils substantially free from asphalts, such as refined minerallubricating oils or lubricants containing them, such as various greases,e. g., soda, soap greases, calcium soap greases, aluminum soap greases,etc.- Oils used; for dipping metals to prevent their being attacked bymoisture or acids in the atmosphere may, if desired, be lighter thanlubricating oils and may comprise gas oil, kerosene or naphtha. Othercompositions for rust protection may comprise petrolatum, paraffin wax,etc.

The amount of paramn wax to be added to mineral lubricating oils to beeffective for my purpose may range from about .25% to 5%, and preferablyfrom around .5% to 2%. Amounts of the carboxylic acids, if added, mayrange from about .1 to 2%, it being preferred that at least a slightexcess of the wax amine over the stoichiometric equivalent of themonocarboxylic acid be present. I

Wax amines of this invention. are reaction products of chlorinatedhydrocarbon wax treated with ammonia under conditions to causeammonolysis. Following is a description of the process by which they aremanufactured:

A parafiin wax or petrolatum is chlorinated by bubbling chlorine throughit, preferably at a temperature between and C. until a chlorine contentabove at least 20% and preferably 25%- 38% by weight is reached. Thechlorinated wax is dissolved in a suitable solvent, such as absoluteethyl alcohol, and ammonia is added thereto in suflicient quantity, e.g., 8%-l0% by weight. The mixture is heated in an autoclave to atemperature of the order of -175 C. which produces a pressure of about300-500 lbs. until ammonolysis is substantially completed, which mayrequire, for example, 6 hours. The ammonium chloride, solvent and excessammonia are then separated by filtration and distillation.-

Wax amines prepared under the above preferred conditions have morepronounced metal-wetting properties than wax amines prepared underdifferent conditions.

The composition and properties of wax amines vary in general within thefollowing normal range:

They are'translucent viscous liquids of amber to brown color having anaverage molecular weight of 450-600; bromine number below 100, usually25-100 (gms. Br/100 gm); a nitrogen content of 3%6%, of which about10%-50% is tertiary and the remainder primary or secondary amines. Atypical sample of wax amin had an average molecular weight of 505,bromine number of 60, contained 5.50% nitrogen, of which 69% was in theform of primary or secondary amines and 31 of tertiary amines.

Thus it can be seen that 'wax amine is a mixture of aliphatic amines,containing no apprecia ble proportion of quaternary ammonium compounds.Most paramn chains carry more than one nitro en and are slightlyunsaturated. However, the molecules contain no aromatic groups.

Carboxylic acids to be added in addition to the wax amine should have atleast 12 carbon atoms and should preferably be saturated, i. e., be freeor substantially free from olefinic double bonds.

hesive properties of the oiL Saturated acids in general are less apt tobreak down through oxidation, and also in general are far more effectivein the matter of enhancin the effect of the wax amines. They shouldpreferably be predominantlyaliphatic, i. e., should contain more thanhalf of their carbon atoms in aliphatic formation, inasmuch as thepredominantly cyclic acids, and particularly the aromatics, are normallyless effective. The acids may be monoor polycarboxylic.

Suitable acids are, for example. lauric, palmitic, stearic, behenic,arachic, phenyl stearic, etc., acids. Other suitable acids may beproduced by oxidation of paraffin wax, for example, by blowing airthrough it at an elevated temperature, if desired, in the presence of anoxidation catalyst. Of the polycarboxylic acids, the alkylated succinicacids and agarlc acids are very suitable. Still other acids are thealkylated' glutaric, adipic, pimelic, suberic, azelaic, sebacic,tricarballylic, wax phthalic, polymerized olelc, etc., acids. Airline,hydroxy, halogen, sulfur, etc.,

derivatives of the above may be used, as, for ex- A ample, hydroxy oramino palmitic or stearic acids, chlorinated or sulfurized fatty oralkyl maleic acids, N-amino bis fatty acids, etc.

In addition to the above compounds, other agents may be added, such asoxidation inhibitors, blooming agents, detergents, etc. The presence ofanti-oxidants, such as oxidation inhibitors or retarders is particularlydesirable, inasmuch as they will not only protect the minerallubricating oil from deterioration, but the wax amine as well. may be ofthe aromatic'hyydroxy or amino type.

Example I The critical adhesion temperature of an oil with and withoutthe wax amine additive was measured asfollows: The critical adhesiontemperature apparatus comprises a 1" x 2" bar of cold rolled steelhaving a trough on one side. The bar is placed in a position of 1inclination to horizontal with the trough on the upper surface. The baris then heated at the lower end so as to maintain there a temperature of400 Two or three dropsof oil to be tested are placed in the trough at apoint where the temperature is exactly 400 F3, and the movement of theoil is then noted. The oil then begins to move up against thegravitational force away from the source of heat. If the, oil has goodadhesion qualities, it will stop at arelatively short distance from thesource of heat. If it has poor adhesion qualities,'it will travelfarther. The temperature of the spot at which the oil stops is thennoted and recorded as the critical adhesion temperature.

A western mineral lubricating oil S. A. E. 30

was tested by the above test. Its critical adhesion temperature was 150F. To a sample of this oil was added 1% of the wax amine and 2.5% of acalcium petroluem sulfonate, the latter being a detergent having noinfluence on the ad- The critical adhesionv temperature rose to 164 F.To another samplewas added 1% wax amine, 5% stearic acid and 2.5% of thecalcium petroleum sulfonate. The critical adhesion temperature now roseto 269 F., and the oil spread up the sides. of the trough. leaving acontinuous film, thus showin: excellent wetting power.

the atmosphere for three days.

period, they were examined with the following Suitable oxidationinhibitors Example If- Stainless steel balls were coated with doped andundoped S. A. E. 30 lubricating oil. The coated balls were placed in a.water bath main- 5 tained at C. After 64 hours, the balls were examinedwith the following results:

Exam le In Mild steel plates were coated with doped and undoped S. A. E.30 lubricating oil. The coated plates were then left undisturbed,exposed to At end of that results:

g Addition agent Condition:l giggstes after None Edges rusted. .5 7 freewax amines Edges somewhat rusted. .5 0 free wax amines-F591, stcaricacidflng No rust.

I claim as my invention:

1. A corrosion-protective composition for metals comprising a. normallynon-gaseous hydrocarbon oil substantially free from asphalt andcontaining dissolved a small amount of a hydrocarbon wax aminesubstantially free from chlorine which amine is a reaction product ofchlorinated paraflin wax and ammonia.

2. The composition of claim 1 wherein said non-gaseous hydrocarboncomprises a. refined lubricating oil.

3. The composition of claim 1 wherein said non-gaseous hydrocarbon is a.petrolatum.

4. A corrosion-protective composition for met-' als comprising anormally non-gaseous hydrocarbon oil substantially free from asphalt andcontaining dissolved a small amount of a hydrocarbon wax aminesubstantially free from chlorine having a molecular weight of about458-660, a nitrogen content of 3%-8% and a bromine number below 100which amine'is a. reaction product :1 chlorinated paraflln wax andammonia. I

5. A corrosion-protective composition for metals comprising a normallynon-gaseous hydrocar bon oil substantially free from asphalt andcontaining dissolved .25%-5% of a hydrocarbon wax amine substantiallyfree from chlorine which amine is a reaction product of chlorinatedparafin wax and ammonia.

'6. A corrosion-protective composition for metals comprising a normallynon-gaseous hydrocarbon oil substantially free from uphalt andcontaining dissolved .5%-2% of a hydrocarb n we! amine substantiallyfree from chlorine whicl a amine is a. reaction product of chlorinatedparaffln-wax and ammonia.

'7. A corrosion-protective composition for met als comprising a.normally non-gaseous hydrocar bon oil substantially nee from asphalt andcon taining dissolved small amounts each of hydro acid having at least12 carbon ems.

'II is saturated.

taining dissolved from .25%-5% of a hydrocar- 10 bon wax aminesubstantially free from chlorine and from .1%-2% of a predominantlyaliphatic saturated carboxylic acid having at least 12 carbon atoms. 13.A corrosion-protective composition for metals comprising a normallynon-gaseous hydrocarbon oil substantially freeirom asphalt andcontaining dissolved from .25%-5% of a hydrocarbon wax aminesubstantially free from chlorine and from .1 %-2% or a saturatedpredominantly aliphatic carboxylic acid having at least 12 carbon atoms,the amount of the waxamine being in excess oi the stoichiometricequivalent of said acid.

14. A blended mineral lubricating oil having anti-corrosive propertiesfor metals and a critical adhesion temperature substantially higher thanthat of said mineral lubricating oil alone, containing dissolved .25%-5%of a hydrocarbon wax amine substantially free from chlorine which amineis a reaction product of chlorinated paraffln wax and ammonia.

15. The composition of claim 7 wherein said acid is a saturatedmonocarboxylic acid.

ALVIN P. ANDERSON.

